The research objective is to study the pathophysiology of compartment syndromes by correlating muscle compartment fluid pressure, as measured by the wick-catheter technique with physical, anatomical, biochemical, histological, circulatory, and neurophysiological parameters. These basic correlates will be applied to clinical cases of compartment syndromes. The wick technique will be used to define the pressure/time relationships with respect to viability and function of muscle and nerve in experimental compartment syndromes. The wick-catheter technique is a simple, accurate, and reliable measurement of compartmental fluid pressure. Biochemical, histological and functional studies will be undertaken to develop definitive criteria for determination of muscle necrosis. Nerve viability and function will be assayed by conduction velocity measurements. Patients with tibial fractures, high tibial osteotomies, or suspected compartment syndromes from other causes will be monitored by the wick-catheter technique for compartmental fluid pressure. Patients with chronic compartment syndromes will be studied by the wick-catheter technique before and after exercise. Finally, the accumulation of these studies should yield sufficient data to permit the evaluation of the compartmental fluid pressure measurement as an objective for decompressive fasciotomy in patients at risk.